Robert abbott hadeield



UNITED STATES KMU-'Fmi @E ILHGME-ITBHL rom-am.

Simmer., ai which thu fnllml'inag invanllzinm4 hns in: abedf i9 Al'iel thin simi ahum that shall Ee auu 'y Buitaburuaslsnpmbectv im st bullets, shrapul and wlilmnndwhi shall oer guasta:- resstnnua to `l'llmfxmion and fra-mim by milsa of 'das d mim-rad im than melsbewuthnmmethibknhmw #nim pmned and whih shall tbamfm be apen-nr ndaptec, im* me ha thu manu mm helmets, bod; shim; md the like in; the una of sulem and athis; enpgn nwannspaw VVim use m sir @mit und for like IE111-pauses but suitable Mm it muy be. ful' pur- Th nmton nlm han for ant to o- :la duce met sum1 helmets muck auch n pmteuw steel;

Fw tha aibuvu nbf new tu this invmm 'iwa Eheptn d wam am spar: .yulp' =rpmma na au mrhlilsnaeurmmmam IIB Il.V mln wel wm iron with from 1Q mi? er of gangancsa und mbon u 'on n at tm: mL hun nsrmallv flgufm n .9 *En 12 or 1 to :s 4% uml l 1t muy ha el: qlumunmfnr inmune or om and copper, as dmbed in o! my nppliuniiom fm- Irtm mi, Burial Nm lil led Ami a Y u Nu. mma 151ml J 1 mi sm;

m. mmm, 51ml J- y 1m m For :ha ufwmlu oftnn shuts uf ma: "um @apn e rmg great tc perforuiin amd imma by 4.5 auch ne droge hammam -wfnrmd tu andthmfnramu'tablsmmsnpm- "taaatnwa1:x|:mi:ixx'1llfl:l'flxl'plllr` Swllm foi-hh; anch maal :ming tu 1h pegfulm ching:-

xmarmtims, mult 'he pmd'nmd upd nml-.ed m w :L spmn! my ilgordm' thm'. have imlmrnu to it tlm mmm qunlims nf 1am with, :wifi

"hmdness and mais turendmvit puble to he mmeesclu y used lar uw ruses nantimmd. Thus, msm 1rn 55 llnfl lmmnbeum man and made Enr mwmumm um ramnma :rune ma, 1920. ltd Lugli# l?, 181?. will Ik Mmm na appghfent. thnmnmntil ihelnm with ome Vmieftal has ldied, so that Bud! appar mnltfenI metal am @ascend am! companimm fm* ahnung# of the metal, dile tu wollgg, Imi thus 11mm! piping and sagl'agntmn that would otlrwnn muur, und thpa enable wund :mm1 ts tu be nbtallinagh whrielpnmershanilto tlm fom 0M au mets e f fm For muffin n @ouml manganese steel ingaat. thug; prmlcad inno simula? g gm?! hardness :md tougmeas n tl'mfuna mztmw tn perforation and immun, the mgot i5 mnm'tad, while nt. l .high um. pmihlremwpslyhabyhmm ini :i5 mmlb It :12d tlmy malt-ing slulr s qnt mno lang s mumble fmthn' mnvpmm'rt pruductmn alswel ulm uf tha :1emred. Enigmas. Baafadm multa 11n-e bm nbtamed b :munfmiuing the metal at im lx f g tmlpmtmlm nf the o1 auf? 151W tlSU Gduringta MEW? hdmmu 11% ,rn,y res am igualmullylemnm und all ar aurama mqmrfeatiqms mmm'erl grinding u1- ulm'wlsa, as wel! as :my split mds un the alb.

Th 11mm ,slab 131mb? ublmiud ianfwrvrmd Gut llbo shorter slab lengths mah hawxl and which is mnvered mlng into mm1 ahem nl tih mqnue hknm This iss duna lagm snm-mim of mllu operations nach (insegnati. to vlrnvcllrme. tha thin uns of the mata] to a mutable degree and tlm; 11mm-nm 'Ld'mordumrmin ofhfe meid., nin ein a gn mettons, t mmgW t :fue ,v uiwt the qualities of the] `nilned 'Insshml staal im the 'hampa-:tum o :ruiling bein hi Swtisfuctory mulls inn-we beim Ubin when using n rolling mmparn. tuna o1 the wiel' of about 11150 tu 1040" C.,

the thm wupmnmm of the nshmd but obtained by the lust mling npmmon being 11n referably about 850 C. Great care should Ee taken during the heating of the slab and resulting lates and sheets, preparator to the severa rolling o rations, to avoi as much as possible, oxidation of such plates and sheets.

The manganese steel sheets thus obtained must then be annealed in a non oxidizinY atmosphere, to remove therefrom the hardness caused by the later stages of the rolling.

The annealed steel sheets are then cut or stamped into lsheets of the size re aired for conversion into helmets, body s lields or other articles. Such sheets are afterward carefully subjected to further heat 'treat ment and water toughened. For this purpose they are first heated ra idly and equally to a. high temperature, t e heating bein carried out in such a manner as practica y to avoid oxidation of the sheets. For this purgoose the sheets may be supported singly a ve the floor of a reheating furnace, as for instance u on small iron bars placed on such floor, t e furnace being so 'red and worked that practically a neutral or non-oxidizing atmosphereis maintained therein. For this mi' ose a gas or oil fired furnace is preferreh. he sheets after being thus equall heated are removed from the furnace an at once quenched in a cold liquid while at a high tem rature. Satisfactory results have been o tained by quenchin the sheets while at a temperature of the or er of about 950 to 1050 C., referably at about 1000 C., in cold water. he whole operation of heating preparatory to quenching, should not occupy more than about two or three minutes.

The manganese steel sheets thus produced nre'then in a condition read to be converted into a helmet or other artic e of the required sha e, as by stamping or pressinr.

he following is a detailed description, given by way of example only, of a method whereby sound manganese steel ingots produced as described, have been converted into thin metal sheets and such sheets converted into helmets that have been found by severe tests to give highly satisfactory results in practice, as regard hardness and tong-lines and consequent resistance toperforation-and fracture.

The manganese steel contained `about 1.25% to 1.4% of carbon and about 13.0% to 13.75% of' manganese. The ingots were of taper shape, cast with their larger ends upward and in the manner hcreinbefore dcscribed to produce sound steel ingot, each ingot being about 9 nare und weighing about 10 to 10.5 cwts. :ich ingot was hammered or pressed at a fox'ng temperature of about 10507 to 1080 into a slab 7 wide and 2 thick and then cut into shorter slab len ths each having a weight of about 56 lbs., t ie metal being heated twice to about the forging temperature hereinbefore mentioned, namely 1050 to 1080 C., to enable it to be properly converted from the ingot form into the finished slab.

Each of the short slab le hs havin a width of 7" and thickness o 2 was t en converted into sheet form by subjecting it to four successive heating and rolling operations as follows First operation-The slab was reheated to u rolling tem rature of about 1030 to 1040" C. and ro led down into a plate or bar 9 wide and i thick, which was then cut into six pieces each about 15 in length.

Second o eration-Each of the said plates was tien reheated to a rolling temperature of about 1030 C. and rolled lon way on into a sheet 18" to 20 in lengt i, 15.75 wide and about .05" thick.

Third operation- The. sheets thus produced were reheated in airs to a temperature of about 1030 C. and) after removing all scale therefrom, were rolled in pairs.

Fourth operation-Each sheet was then again reheated and rolled so as to produ a s eet about 50" long, 15.75" wide 'and of c thickness of about .086" that is to say, of No. 20 gage, the finishing teniierature of the sheet being about 850 C. lsuring each reheatiug, great care was teken to avoid, as far as possible, oxidation` of the sheets, by maintaining a non oxidizing atmosphere iu the reheating furnace.

Out of each of the rolled sheets thus 4produced, three disks each 14.25" in diameter were stamped, each disk being suitable for Oniihfehmi d d i b e ore e' ivi e( y stamping into helmet blankusx,g the rolled sheets, were, in order to remove therefrom the hardness caused by the later stages ofthe rolling, annealed, as by introducmg them into afur nace, such as a mill furnace, und heating them to a tem erature of about 700 to 750 C., after whici they were taken out of the furnace and cooled in piles.

Frein the annealed sheets circular sheets weie stamped to form the helmet blanks. The helmet blanks were heated separately and equally in a non-oxidizing atmosphere to a high tem rature in a gas fired furnace for two or t ree minutes and withdrawn from the furnace at a tempemture of from 950 to 1050 C., but preferably about 1000 C., and quenched in cold water, this fof ming the heat `treatment and ltougheumg treatment of the sheets hereinbefore de-y scribed.

The circular helmet blanks were then placed in aprcss and stamped in' a die to 125 the desired nished shape `for instance that of a concave circular or oval bowl or dish.

To enable `this to be done successfully it is necessary that each circular steel sheet blank should be flat and the edge portion thereof lubricatedall around before putting it into thepress and care must be taken to obtain a very even bearing for the sheet on the diebefore the pressing to shape. takes place otherwise distortion of the sheet will result.

Instead of stamping circular blanks out of the rolled sheet the latter may be cut into square or rectangular sheets and heat treate and toughened as described, such sheets being afterward stamped to the circular or other desired shape as and where required fr conversion, into helmets or other articles.

into a sheet of the desired thickness by a 'temperature of about 10500 to 10800 1. The manufacture of sheet manganese steel which consists in gradually reducing a slab of ,manganese steel by a succession of rolling operations While at a suitable forgin temperature into asheet of the desired thickness and so that the temperature of the sheet at the last rollin operation is of the order of about 850 annealing the resulting sheet, heating the annealed sheet ra idly and equally and for a short time on y, to a high temperature and then plunging it into a cold liquid.

2. The manufacture of manganese steel sheets suitable for use as a protective material as set forth, which consists in casting a sound ingot of manganese steel, converting such ingot into a billet or slab while at an average temperature of about ,10500 to 1080o C., cutting said slab into shorter slab lengths, gradually reducing such slab lengths while at a suitable forging temperature into sheets of the desired thickness, annealing the resulting sheets, heating the annealed sheets rapidly and equally and for a short time onlSy to a high temperature and then cooling them suddenly.

3. The manufacture of manganese steel sheets suitable for use as a protective mat-erial as set forth, which consists in casting a sound ingot of manganese steel, converting such ingot into a ,billet or slab at an average temperature of about 10500 to 10800 (1 cuttin y said slab lengths into shorter slab lent s, gradually reducingsaid slab lengths y rolling into sheets of the desired thickness at a temperature of about 10300 to 10400 C., annealing said sheets and subjecting the annealed sheets to a heat treat` ment and to a Watertoughening .treatment consisting in heating them to a high temperature for a short time only and sud denly cooling them by immersion in colo liquid.

i 4. The manufacture of thin manganese steel sheets, suitable for use as a protective material assetforth; whichV consists in casting a sound ingot of manganese steel, con verting said ingot at an average forging C. mto a slab and cutting said slab into shorter slab lengths, rolling each slab length ofv metal .10400 C. and after rolling, except the lasty one, being reheated to a tem erature of about 10300 C. to 10400 C., t e finishing temperature of the sheet, after the last rolling, beinV about 8500 C. annealing the resultin s eet, heating the annealed sheet rapidy and equally to a temperature of about 9500 to 10500 C. and then plunging it While at about this temperature into a cold liquid, the duration of such heat treatment of the sheets being of the order of about a few minutes.

5. The manufacture of thin manganese steel* sheets, suitable 'for use as a protective material as set forth, which consists in gradually rolling a plate or slab into a sheet of the desired thickness by a succession of rolling operations, the metal at the commencement of such rolling operation bein]r at a temperature of about `1030o to 10400 f., and after rolling, except the last one, being reheated to a temperature `of about 10300 C.

to 10400 C., the finishing temperature of theV sheet, after the last rolling, being about 8500 C., annealing the resulting sheet, heatin the annealed sheet rapidly and equally to a igh temperature for a' short time only and then plunging it While at a high temperature into a cold liquid.

6. The manufacture of thin manganese steel sheets, suitable for use as a protective material as setV forth, which consists in gradually converting a plate or slab of manganese-steel into a sheet of the required thickness and'size by a series of rolling operations with intermediate reheating operato 10500 C. and then plunging it .while at about this temperature into cold Water.

7 The m'an'ufacture of a thin manganese steel blank, suitable for use as a protective device as set forth, which consists in converting a late or slab of man anese steel into sheet orm by a series of rolling operations with intermediate reheating operations, the average rolling temperature being of the order o'f about 1030 to 10400 C. and the finishingteinperature after the last rolling operation, being about 850 C., annealing the resulting sheet, cutting a blank of the desired size and shape from the annealed sheet, reheating the annealed sheet metal blank, rapidly and equally for a few minu only to a temperature of the order of about 950"` to 10500 C., then plunging it wliile at about this temperature into cold water, and forming the resulting blank into an article of the desired shape by pressure.

8. The manufacture of a thin manganese steel blank, suitable for use as a protective material as set forthl`wliieli consists 'in gradual] i reducing a plate or slab of manganese snee by successive rollingbr operations and while at an average temperature of about 1030 to 104()o C. into a sheet of the desired thickness and size, annealing the resulting sheet, cutting a blank of the desired shape and size from the annealed Sh'et, heatin the annealed sheet metal blank apidl an equally to a temperature of the or er about 950 to 10500 C., for a short time only, 15 then lunging it while at about the sind teinpe ature inte a cold liquid, lubricatin the edge portion of the resulting toughene blank and pressing ,the said blank, while supported evenly, into the shape of the cle- 20 sired article.

Signed at 22 Carlton House Terrace, in the city of Westminster, England, this twelfth da of Jul 1917.5

ROB *RT AB OTT HADFIELD. lVitnesses:

WILLIAM CROSS,

LEONARD ROWLAND. 

